ANATOMY AND PHYSIOLOGY
end of the inferior concha is served by the anterior dental branch of the
Secretory nerve fibres supplying the glands and unstriped muscle belong to
the sympathetic and parasympathetic systems. Sympathetic fibres, which
produce vasoconstriction and diminished secretion, arise from the superior
cervical ganglion via the nerve of the pterygoid canal to the pterygopalatine
ganglion. Parasympathetic fibres, which produce vasodilatation and increased
Fig. 4. Lateral wall of left nasal cavity with the middle concha removed; the lateral wall of the middle
meatus is exposed, and the position of the ostia of the sinuses is indicated by arrows. 1, Right sphenoidal
sinus; 2, Sphenoidal ostium; 3, Left sphenoidal sinus; 4, Superior meatus; 5, Inferior meatus; 6,
Inferior concha; 7, Accessory ostium of maxillary sinus; 8, Uncinate process; 9, Ethmoidal bulla; 10,
Infundibulum or semilunar groove; II, Nasofrontal duct; 12, Left frontal sinus; 13, Superior concha;
14, Ostium of posterior ethmoidal cells; 15, Spheno-ethmoidal recess.
secretion, are carried in the greater superficial petrosal nerve and the nerve of
the pterygoid canal to the pterygopalatine ganglion from which post-
ganglionic fibres are distributed.
The olfactory nerves—some twenty filaments—derive from the olfactory
bulb, enter the nasal cavity through the cribriform plate of the ethmoid, and
are distributed in a network in the mucous membrane in the upper third of the
nasal septum and the lateral wall of the nasal cavity. The perineural sheaths of
these filaments communicate directly with the pia-arachnoid and thus may
transmit infection to the^eninges.
PHYSIOLOGY OF THE NOSE
The functions of the nose are respiratory and olfactory.
Respiratory. The nose is the normal method of respiration, and a baby born
with an occlusion of both posterior nares makes strenuous efforts at nasal